Parent Guarantor - Schedule of Condensed Consolidating Balance Sheets (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Assets:
Cash and cash equivalents	$ 16,112		$ 32,774		$ 107,379		$ 314,466
Accounts receivable, net of allowance for doubtful accounts	54,440		72,943
Other current assets	17,163		84,064
Property and equipment, net	2,137,664		2,029,523
Investment in subsidiaries	0		0
Noncurrent assets	13,309		33,156
Total	2,238,688		2,252,460
Liabilities and Stockholders' Equity:
Accounts payable and other accrued liabilities	119,809		131,379
Other current liabilities	83,955		116,806
Long-term debt, net of debt issuance costs	768,149		617,387
Deferred income taxes	109,933		139,534
Other noncurrent liabilities	40,449		35,256
Stockholders' equity	1,116,393	$ 1,116,475	1,212,098	$ 987,797	1,015,203	$ 1,060,340	598,554
Total liabilities and stockholders' equity	2,238,688		2,252,460
Intercompany Eliminations
Assets:
Cash and cash equivalents	0		0		0		0
Accounts receivable, net of allowance for doubtful accounts	0		0
Other current assets	0		0
Property and equipment, net	0		0
Investment in subsidiaries	(1,116,393)		(1,212,098)
Noncurrent assets	0		0
Total	(1,116,393)		(1,212,098)
Liabilities and Stockholders' Equity:
Accounts payable and other accrued liabilities	0		0
Other current liabilities	0		0
Long-term debt, net of debt issuance costs	0		0
Deferred income taxes	0		0
Other noncurrent liabilities	0		0
Stockholders' equity	(1,116,393)		(1,212,098)
Total liabilities and stockholders' equity	(1,116,393)		(1,212,098)
Parent Guarantor | Reportable Legal Entities
Assets:
Cash and cash equivalents	0		0		0		0
Accounts receivable, net of allowance for doubtful accounts	0		0
Other current assets	0		0
Property and equipment, net	0		0
Investment in subsidiaries	1,116,393		1,212,098
Noncurrent assets	0		0
Total	1,116,393		1,212,098
Liabilities and Stockholders' Equity:
Accounts payable and other accrued liabilities	0		0
Other current liabilities	0		0
Long-term debt, net of debt issuance costs	0		0
Deferred income taxes	0		0
Other noncurrent liabilities	0		0
Stockholders' equity	1,116,393		1,212,098
Total liabilities and stockholders' equity	1,116,393		1,212,098
Subsidiary Issuer | Reportable Legal Entities
Assets:
Cash and cash equivalents	16,112		32,774		$ 107,379		$ 314,466
Accounts receivable, net of allowance for doubtful accounts	54,440		72,943
Other current assets	17,163		84,064
Property and equipment, net	2,137,664		2,029,523
Investment in subsidiaries	0		0
Noncurrent assets	13,309		33,156
Total	2,238,688		2,252,460
Liabilities and Stockholders' Equity:
Accounts payable and other accrued liabilities	119,809		131,379
Other current liabilities	83,955		116,806
Long-term debt, net of debt issuance costs	768,149		617,387
Deferred income taxes	109,933		139,534
Other noncurrent liabilities	40,449		35,256
Stockholders' equity	1,116,393		1,212,098
Total liabilities and stockholders' equity	$ 2,238,688		$ 2,252,460